Workaround for IPv6Net /64 anomaly in netaddr gem

cloudfoundry · Apr 7, 2022 · 3414bce · 3414bce
1 parent d40d9b7
commit 3414bce
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Showing 3 changed files with 29 additions and 12 deletions.
diff --git a/src/bosh-director/lib/bosh/director/ip_util.rb b/src/bosh-director/lib/bosh/director/ip_util.rb
@@ -98,13 +98,17 @@ def to_s
       private
 
       def parse(cidr)
-        NetAddr::IPv4Net.parse(cidr)
+        cidr = NetAddr::IPv4Net.parse(cidr)
       rescue NetAddr::ValidationError => e_v4
         begin
-          NetAddr::IPv6Net.parse(cidr)
+          cidr = NetAddr::IPv6Net.parse(cidr)
+          if cidr.netmask.prefix_len <= 64
+            raise "Unsupported CIDR prefix length. Please choose a CIDR mask numerically larger than /64."
+          end
         rescue NetAddr::ValidationError => e_v6
           raise NetAddr::ValidationError, "IP CIDR format #{ip} is neither a valid IPv4 nor IPv6 format: #{e_v4} / #{e_v6}"
         end
+        cidr
       end
     end
 

diff --git a/src/bosh-director/spec/unit/cidr_range_combiner_spec.rb b/src/bosh-director/spec/unit/cidr_range_combiner_spec.rb
@@ -92,15 +92,15 @@ module Bosh::Director
         [
           NetAddr::IPv4Net.parse('192.168.0.8/30'),
           NetAddr::IPv6Net.parse('fd7a:eeed:e696:968f:0000:0000:0000:0005/128'),
-          NetAddr::IPv6Net.parse('fd7a:eeed:e696:968f:0000:0000:0000:0005/64'),
+          NetAddr::IPv6Net.parse('fd7a:eeed:e696:968f:0000:0000:0000:0005/96'),
           NetAddr::IPv4Net.parse('192.168.0.20/32'),
         ]
       end
 
       it 'combines the ranges' do
         expect(range_combiner.combine_ranges(cidr_ranges)).to eq(
           [['192.168.0.8', '192.168.0.11'], ['192.168.0.20', '192.168.0.20'],
-           ['fd7a:eeed:e696:968f:0000:0000:0000:0000', 'fd7a:eeed:e696:968f:ffff:ffff:ffff:ffff']],
+           ['fd7a:eeed:e696:968f::', 'fd7a:eeed:e696:968f::ffff:ffff']],
         )
       end
     end

diff --git a/src/bosh-director/spec/unit/deployment_plan/manual_network_subnet_spec.rb b/src/bosh-director/spec/unit/deployment_plan/manual_network_subnet_spec.rb
@@ -86,7 +86,7 @@ def create_dynamic_reservation(ip)
     it 'should create an IPv6 subnet spec' do
       subnet = make_subnet(
         {
-          'range' => 'fdab:d85c:118d:8a46::/64',
+          'range' => 'fdab:d85c:118d:8a46::/96',
           'gateway' => 'fdab:d85c:118d:8a46::1',
           'reserved' => [
             'fdab:d85c:118d:8a46::10-fdab:d85c:118d:8a46::ff',
@@ -105,16 +105,29 @@ def create_dynamic_reservation(ip)
         [],
       )
 
-      expect(subnet.range.ip).to eq('fdab:d85c:118d:8a46:0000:0000:0000:0000')
-      subnet.range.ip.size == 2**64
-      expect(subnet.netmask).to eq('ffff:ffff:ffff:ffff:0000:0000:0000:0000')
-      expect(subnet.gateway).to eq('fdab:d85c:118d:8a46:0000:0000:0000:0001')
+      expect(subnet.range.network.to_s).to eq('fdab:d85c:118d:8a46::')
+      # subnet.range.ip.size == 2**64  # TODO NETADDR: bug? / what was tested here?
+      expect(subnet.netmask).to eq('ffff:ffff:ffff:ffff:ffff:ffff::')
+      expect(subnet.gateway.to_s).to eq('fdab:d85c:118d:8a46::1') # TODO NETADDR: not sure how it worked before (was previously an object as well)
       expect(subnet.dns).to eq([
-        "2001:4860:4860:0000:0000:0000:0000:8888",
-        "2001:4860:4860:0000:0000:0000:0000:8844",
+        "2001:4860:4860::8888",
+        "2001:4860:4860::8844",
       ])
     end
 
+    it 'should fail for <= /64 IPv6 CIDR prefixes' do
+      expect {
+        make_subnet(
+          {
+            'range' => 'fdab:d85c:118d:8a46::/64',
+            'gateway' => 'fdab:d85c:118d:8a46::1',
+            'cloud_properties' => {'foo' => 'bar'},
+          },
+          []
+        )
+      }.to raise_error(/Unsupported CIDR prefix length/)
+    end
+
     it 'should require a range' do
       expect {
         make_subnet(
@@ -385,7 +398,7 @@ def create_dynamic_reservation(ip)
     it 'should return false when IPv4 and IPv6 ranges are compared' do
       other = make_subnet(
         {
-          'range' => 'f1ee:0000:0000:0000:0000:0000:0000:0000/64',
+          'range' => 'f1ee:0000:0000:0000:0000:0000:0000:0000/96',
           'gateway' => 'f1ee:0000:0000:0000:0000:0000:0000:0001',
           'cloud_properties' => { 'foo' => 'bar' },
         },